Detonators for ammunitions



ATTORNEY Oct. 28, 1958 L. A. M. LINDNER ETAL DEToNAToRs FOR AMMUNITIoNs Fild sept. 22, 1954 United States Patent C) DETNATRS FR AlVllv/[UNITIONS Lars Anders Malte Lindner and Stig Yngve Ek, Sundbyberg, Sweden Application September 22, 1954, Serial No. 457,723

2 Claims. (Cl. 102-70) It sometimes loccurs that accidental explosions take place in ammunitions the bursting charge of which is adapted to lbe detonated by means of an initiating charge of an azide, for instance lead azide or other azide which is capable of yielding hydrazoic acid. Such explosions are particularly apt to occur in ammunitions the fuze or igniting device of which is made of yor contains metal or metals such :as copper, cadmium, nickel or phosphorbronze or alloys thereof. Investigations for ascertaining the cause of the accidental explosions have disclosed that said metal or metallic components will form very shocksensitive azides in the presence of moisture which often is present in or easily may penetrate into all kinds of ammunition.

The object of the present invention is to provide means to prevent such :accidental explosions. This is accomplished according to the invention by introducing into the fuze a metallic substance having a greater chemical afiinity to hydrazoic 'acid than the metallic components and reacting with the hydrazoic acid to form a nonexplosive or less explosive azide. Said reactive metallic substance preferably consists of magnesium or zinc which are both capable of decomposing the hydrazoic acid. Instead of magnesium or zinc compounds of said metals or of other metals may be used which are capable of reacting with the hydrazoic acid to form a non-explosive azide. The metallic substance may be introduced either in a solid state or in the storm of a piece of compressed metal powder. As magnesium or zinc will form no dangerous azides such a metallic substance may be placed inside the detonator cap or in its vicinity other metallic substances which will react with the hydrazoic acid to form a compound that is explosive to a certain extent but in a substantially lesser degree than the compound produced by the reaction of the hydrazoic acid with the metallic components of the fuze should be located outside or as far as possible away from the detonator cap at a place where the azide formed cannot initiate the charge should it explode. The metallic substance should, preferably, not constitute any part of the fuze or the igniting mechanism itself but should form a separate element introduced only for the purpose mentioned.

The invention is illustrated in the accompanying drawing which shows schematically a grenade provided with a fuze according to the invention.

In the fore part of the grenade shell 1, lled with the bursting charge 2, there is provided a fuze 3 comprising a booster container 4 1holding the booster charge 5, an igniting mechanism, and a detonator. In the example shown the igniting mechanism is assumed to consist of a striking pin 6 and a releasing device 7. The detonator is inserted in the .booster and consists of a detonator cap 8 holding the initiating charges, viz. a primer charge 11, an intermediate charge 10 consisting of an azide compound, for instance lead azide, and a third charge 9, for instance pentolite or tetryl. When the striking pin is released it will pierce the primer charge 11 and strike the intermediate charge 10, thus causing the third charge 9 and the booster charge 5 to initiate the bursting charge 2 `of the grenade. The primer charge 11 may be missing and the striking pin 6 may initiate the intermediate charge 10 directly.

According to the invention the detonator is provided with a reactive safety element 12 consisting of a metallic substance having a greater chemical aflinity to the hydrazoic acid than the metallic components of the fuze and being capable of forming a non-explosive or less explosive azide compound. Said element preferably consists of magnesium or zinc in the form of compressed powder or a solid piece of said metal. In the example shown it has the shape of a ring or disk placed in the fore compartment of the fuze around the projecting end of the detonator cap.

The invention -may be modified in many ways and is not limited Ito t-he embodiments above described. It may be applied to fuzes for any kind of ammunition such as projectiles and bombs.

What is claimed is:

1. An ammunition fuze for explosive projectiles comprising a detonator having an initiating charge containing at least one azide and yielding hydrazoic acid when in :contact with moisture, a plurality of diierent metallic components including an ignition mechanism which is positioned for operating said detonator, certain of said components enclosing said detonator and being exposed to vapours of hydrazoic acid given off by the initiating charge and reacting with the vapours to form unstable compounds comprising shock-sensitive Iazides, and a chemically reactive element exposed to vapours of t-he hydrazoic acid comprising a metallic substance having a greater chemical ainity to the Ihydrazoic acid and vapours than said metallic components and reacting with the hydrazoic acid and vapours thereof to form a nonexplosive compound `so as to preclude formation of said unstable compounds comprising the shock-sensitive azides, said reactive element comprising a part separate from the metallic components of the fuze and disposed outside of the detonator.

2. An ammunition fuze for explosive projectiles comprising a detonator having an initiating charge containing at least one azide and yielding hydrazoic acid when in contact with moisture, a plurality of different metallic components including an ignition mechanism positioned for operating said detonator and disposed so as to dene at least one compartment, certain of said same metallic components coming in contact with hydrazoic acid vapours given olf by the initiating charge so as to react with said acid vapours to form unstable compounds comprising shock-sensitive azides, said compartment being disposed to receive the detonator and vapours of said hydrazoic acid, and a chemically reactive element located sin said compartment in selected position outside of the detonator and adjacent said initiating charge and exposed to `the vapours of `said hydrazoic acid, said reactive element comprising a part separate from the metallic components of the fuze and having a greater chemical afinity to the hydrazoic acid and vapours than said metallic components and reacting with the hydrazoic acid and vapours thereof to form a non-explosive compound therewith and to preclude formation of said unstable compounds comprising shock-sensitive azides.

References Cited in the tile of this patent UNITED STATES PATENTS 2,178,723 Forsyth Nov. 7, 1939 2,255,600 Salzberg Sept. 9, 1941 FOREIGN PATENTS 363,671 Great Britain 1932. 

1. AN AMMUNITION FUZE FOR EXPLOSIVE PROJECTILES COMPRISING A DETONAROT HAVING AN INITIATING CHARGE CONTAINING AT LEAST ONE AZIDE AND YELIDING HYDRAZONIC ACID WHEN IN CONTACT WITH MOISTURE, A PLURALITY OF DIFFERENT METALLIC COMPONENTS INCLUDING AN IGNITION MECHANISM WHICH IS POSITIONED FOR OPERATING SAID SETONATOR, CERTAIN OF SAID COMPONENTS ENCLOSING SAID SETONATOR, CERTAIN OF SAID TO VAPORS OF HYDRAZONIC ACID GIVEN OFF BY THE INITIATING CHARGE AND REACTING WITH THE VAPOURS TO FORM UNSTABEL COMPOUNDS COMPRISING SHOCK-SENSITIVE AZIDES, AND A CHEMICALLY REACTIVE ELEMENT EXPOSED TO VAPORS OF THE HYDRAZOIC ACID COMPRISING A METALLIC SUBSTANCE HAVING A GREATER CHEMICAL AFFINITY TO THE HYRAZOIC ACID THE VAPORS THAN SAID METALLIC COMPONENTS AND REACTING WITH THE HYDRAZOIC ACID AND VAPORS THEREOF TO FORM A NONEXPLOSIVE COMPOUND SO AS TO PRECLUDE FROMATION OF SAID UNSTABLE COMPOUNDS COMPRISING THE SHOCK-SENSITIVE AZIDES, SAID REACTIVE ELEMENT COMPRISING A PART SEPARATE FROM THE METALLIC COMPONENTS OF THE FUZE AND DISPOSED OUTSIDE OF THE DETONATOR. 